Orthopaedic surgical saw assembly for removing an implanted glenoid component and method of using the same

ABSTRACT

A surgical instrument for removing an implanted glenoid component from the glenoid of a patient includes a protective cannula and a flexible wire saw. The flexible wire saw is positioned in the protective cannula such that both ends of the flexible wire saw extend out of one end of the protective cannula, with a portion of the middle section of the wire saw forming a loop that extends out of the other end of the protective cannula. Surgical methods for the use of such a surgical instrument are also disclosed.

This application claims priority to and is a divisional application ofU.S. patent application Ser. No. 14/231,027, now U.S. Pat. No.10,390,970, which is a divisional application that claims priority toU.S. patent application Ser. No. 13/371,979, now U.S. Pat. No.8,696,677, each of which is expressly incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to an orthopaedic instrumentfor use in the performance of an orthopaedic joint replacementprocedure, and more particularly to an orthopaedic surgical saw assemblyfor removing an implanted glenoid component.

BACKGROUND

During the lifetime of a patient, it may be necessary to perform a totalshoulder replacement procedure on the patient as a result of, forexample, disease or trauma. In a total shoulder replacement procedure, ahumeral component having a prosthetic head is used to replace thenatural head of the patient's humerus. The humeral component typicallyincludes an elongated stem that is implanted into the intramedullarycanal of the patient's humerus. In such a total shoulder replacementprocedure, the natural glenoid surface of the scapula is resurfaced orotherwise replaced with a glenoid component that provides a bearingsurface upon which the prosthetic head of the humeral componentarticulates.

From time-to-time, revision surgery is performed to replace apreviously-implanted glenoid component. In such a revision surgery, thepreviously implanted glenoid component is surgically removed and areplacement glenoid component is implanted in the patient's glenoid. Thesubcondylar plate may be damaged or missing subsequent to revisionsurgery. Revision surgery may also result in defects, some of which maybe fairly large, in the cancellous bone of the glenoid vault of thescapula. Fixation of a revision glenoid component can be difficult toachieve with the limited bone remaining on the glenoid vault of thescapula after the revision surgery has been performed.

SUMMARY

According to one aspect, a method of surgically removing an implantedglenoid component from the glenoid of a patient includes positioning aflexible wire saw between a medial surface of a platform of theimplanted glenoid component and the glenoid of the patient. The flexiblewire saw is then reciprocated so as to cut through one or more anchorsextending from the medial surface of the platform of the implantedglenoid component. The platform of the implanted glenoid component isthen removed from the glenoid of the patient such that the one or morecut anchors remain in the glenoid of the patient.

The method also includes operating a surgical tool so as to remove theone or more cut anchors from the glenoid of the patient subsequent toremoval of the platform of the implanted glenoid component. In anembodiment, the cut anchors are drilled from the glenoid of the patientwith a surgical drill.

The flexible wire saw may be initially positioned behind thesuperior-most edge of the implanted glenoid component and thereafteradvanced inferiorly from the superior-most edge of the implanted glenoidcomponent to the inferior-most edge of the implanted glenoid component.

The flexible wire saw may be positioned in a protective cannula suchthat the flexible wire saw forms a loop extending out of the cannula,with such a loop being positioned between the medial surface of theplatform of the implanted glenoid component and the glenoid of thepatient. In such an embodiment, the flexible wire saw is reciprocatedwithin the protective cannula.

The protective cannula may be embodied as a dual-lumen cannula such thata first end of the flexible wire saw extends out of a first end of thefirst cannula, with a second end of the flexible wire saw extending outof a first end of the second cannula. The middle section of the flexiblewire saw extends between a second end of the first cannula and a secondend of the second cannula.

The flexible wire saw may be embodied as a Gigli saw.

The flexible wire saw may be manually reciprocated so as to cut throughthe one or more anchors extending from the medial surface of theplatform of the implanted glenoid component. Alternatively, it may bereciprocated with a power tool.

According to another aspect, a surgical instrument for removing animplanted glenoid component from the glenoid of a patient includes aprotective cannula and a flexible wire saw. The flexible wire saw ispositioned in the protective cannula such that both ends of the flexiblewire saw extend out of one end of the protective cannula, with a portionof the middle section of the wire saw forming a loop that extends out ofthe other end of the protective cannula.

The protective cannula may be embodied as a dual-lumen cannula such thata first end of the flexible wire saw extends out of a first end of thefirst cannula, with a second end of the flexible wire saw extending outof a first end of the second cannula. The middle section of the flexiblewire saw extends between a second end of the first cannula and a secondend of the second cannula.

The flexible wire saw may be embodied as a Gigli saw.

The protective cannula is metallic or polymeric.

According to another aspect, a method of surgically resecting thehumeral head of a patient includes positioning a flexible wire saw incontact with the humeral head of the patient, and reciprocating theflexible wire saw so as to cut through the humeral head of the patientso as to create a substantially planar surgically prepared surface.

The flexible wire saw may initially be positioned in contact with theposterior surface of the humeral head of the patient, and thereafteradvanced anteriorly so as to create a substantially planar surgicallyprepared surface.

The flexible wire saw may be positioned in a protective cannula suchthat the flexible wire saw forms a loop extending out of the cannulathat is positioned in contact with the humeral head of the patient. Insuch an embodiment, the flexible wire saw is reciprocated within theprotective cannula.

The protective cannula may be embodied as a dual-lumen cannula such thata first end of the flexible wire saw extends out of a first end of thefirst cannula, with a second end of the flexible wire saw extending outof a first end of the second cannula. The middle section of the flexiblewire saw extends between a second end of the first cannula and a secondend of the second cannula.

The flexible wire saw may be embodied as a Gigli saw positioned incontact with the humeral head of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the following figures,in which:

FIG. 1 is a perspective view of an orthopaedic surgical saw assembly;

FIG. 2 is a perspective view of the dual-lumen cannula of the sawassembly of FIG. 1; note that a portion of the cannula has been cutawayfor clarity of description;

FIG. 3 is an exploded perspective view showing a glenoid componentimplanted in the glenoid of a patient during a primary orthopaedicsurgical procedure;

FIG. 4 is a perspective view showing the flexible wire saw of the sawassembly of FIG. 1 looped over the glenoid component during a revisionsurgical procedure to remove the glenoid component;

FIG. 5 is a fragmentary cross section view showing the flexible wire sawof the saw assembly of FIG. 1 being advanced through the anchors of theglenoid component;

FIG. 6 is a perspective view showing a drill being used to drill out theanchors of the glenoid component after its platform has been removedwith the saw assembly of FIG. 1;

FIG. 7 is a perspective view showing the saw assembly of FIG. 1 beingused to resect the natural humeral head of a patient; and

FIG. 8 is a view similar to FIG. 7, but showing the humeral head of thepatient after it has been resected by use of the saw assembly of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

Terms representing anatomical references, such as anterior, posterior,medial, lateral, superior, inferior, etcetera, may be used throughoutthis disclosure in reference to both the orthopaedic implants describedherein and a patient's natural anatomy. Such terms have well-understoodmeanings in both the study of anatomy and the field of orthopaedics. Useof such anatomical reference terms in the specification and claims isintended to be consistent with their well-understood meanings unlessnoted otherwise.

Referring now to FIGS. 1 and 2, there is shown an orthopaedic surgicalinstrument 10 for removing an implanted glenoid component 12 from theglenoid 14 of a patient (see also FIG. 3). The surgical instrument 10 isembodied as a surgical saw assembly and, in the illustrative embodimentdescribed herein, includes a flexible wire saw 16 and a protectivecannula 18. The flexible wire saw 16 is embodied as a braided metalliccutting wire having a loop 20 formed in each of its ends. A handle 22 issecured to each end of the flexible wire saw 16 by inserting thehandle's hook 24 into the loop 20. A surgeon grasps each handle toreciprocate the flexible wire saw 16 during its use in an orthopaedicsurgical procedure. In the illustrative embodiment described herein, theflexible wire saw 16 is embodied as a commercially-available Gigli saw.

As can be seen in FIGS. 1 and 2, the flexible wire saw 16 is positionedin the protective cannula 18 such that both ends 26, 28 of the flexiblewire saw 16 extend out of one end 30 of the protective cannula 18, witha middle section 32 of the flexible wire saw 16 forming a loop 34 thatextends out of the other end 36 of the protective cannula 18. In theillustrative embodiment described herein, the protective cannula 18 isembodied as a dual-lumen cannula. As such, it is embodied as a pair ofseparate cannulae 40, 42 secured to one another by a connecting plate44. In such an arrangement, one end 26 of the flexible wire saw 16extends out of an end 46 of the cannula 40, with the other end 28 of theflexible wire saw 16 extending out of an end 48 of the cannula 42. Theloop 34 formed from the middle section 32 of the flexible wire saw 16extends between the respective opposite ends 52, 54 of the cannulae 40,42.

Each of the cannulae 40, 42 has an elbow 56 formed near its respectivedistal end 52, 54. Such a shape facilitates proper positioning of theloop 34 formed from the middle section 32 of the flexible wire saw 16during a cutting procedure.

Positioning the flexible wire saw 16 in the protective cannula 18protects the patient's surrounding tissue during an orthopaedicprocedure. Specifically, the protective cannula 18 prevents the movingflexible wire saw 16 from contacting the tissue surrounding the surgicalsite as the saw 16 is reciprocated back and forth within the surgicalsite. Moreover, the protective cannula 18 prevents the flexible wire saw16 from slipping as it is operated.

Referring now to FIGS. 4-6, there is shown a revision surgical procedurein which the surgical saw assembly 10 is used to surgically remove apreviously implanted glenoid component 12 from the glenoid 14 of apatient. As can be seen in FIG. 3, in a previous primary procedure, theglenoid component 12 is implanted in the patient's glenoid 14. A typicalglenoid component 12 includes a platform 62 having a concave lateralsurface 64 that provides a smooth bearing surface upon which a naturalor prosthetic humeral head articulates. The platform 62 also has aconvex medial surface 66 that is opposite its concave lateral surface64.

The glenoid component 12 also includes a number of anchors 68 extendingperpendicularly from the medial surface 66 of the glenoid component 12.For example, as shown in FIG. 3, the component's anchors 68 may take theform of a finned central peg 70 that is inserted into a hole 72 drilledor otherwise formed in the patient's glenoid 14 during the previoussurgical procedure. The glenoid component's anchors 68 may also includea plurality of stabilizing pegs 74 that are received into a number ofcorresponding holes 76 drilled or otherwise formed in the glenoid 14 ofthe patient's scapula during the previous surgical procedure. Althoughthe anchors 68 of the glenoid component 12 have herein been described aspegs, other types of anchors are commonly used in the design of glenoidcomponents. For example, the glenoid component's anchors 68 may beembodied as keels, fins, posts, or any other type of anchor.

Typically, the glenoid component 12 is embodied as a monolithic moldedcomponent. That is, the platform 62 and the anchors 68 are integrallymolded using a polymer such as polyethylene. One example of acommonly-used polyethylene is ultrahigh molecular weight polyethylene(UHMWPE).

During a revision surgery, it may be necessary to remove the previouslyimplanted glenoid component 12 from the patient's glenoid 14. As shownin FIGS. 4-6, the surgical saw assembly 10 may used to surgically removea previously implanted glenoid component 12 without leaving a large voidin the patient's glenoid 14. To do so, the patient's soft tissue isdissected and retracted to allow access to the glenoid 14. Full (i.e.,360°) exposure of the bony glenoid is typically achieved.

As shown in FIG. 4, a plane 41 extends through each cannula 40, 42 ofthe protective dual-lumen cannula 18. The flexible wire saw 16 extendsthrough the dual-lumen cannula 18 in a first orientation that is planarto the plane 41. The flexible wire saw 16 forms a loop 34 that extendsoutwardly from the distal ends 52, 54 of each elbow 56 in a secondorientation that is angled out of the plane 41. The distal end 36 of theprotective cannula 18 is then inserted into the surgical site formed bythe dissected and retracted soft tissue. The surgeon then positions theflexible wire saw behind the platform 62 of the implanted glenoidcomponent 12. In particular, the surgeon slips the loop 34 formed by themiddle section 32 of the flexible wire saw 16 between the convex medialsurface 66 of the glenoid component's platform 62 and the glenoid 14 ofthe patient's scapula. In the illustrative embodiment described herein,the surgeon slips the loop 34 formed by the middle section 32 of theflexible wire saw 16 behind the superior-most edge 78 of the glenoidcomponent's platform 62.

If not already installed, the surgeon then secures a handle 22 to eachend of the flexible wire saw 16 by inserting the handle's hook 24 intothe loops 20 formed on the ends 26, 28 of the saw 16. The surgeon thengrasps a handle 22 with each hand and reciprocates or otherwise pullsthe flexible wire saw 16 back and forth. The surgeon also appliesdownward pressure on the flexible wire saw 16 so that it advancesinferiorly. As the flexible wire saw 16 is advanced inferiorly away fromthe superior-most edge 78 of the glenoid component's platform 62 in thedirection toward its inferior-most edge 80, the reciprocating motion ofthe saw 16 abrades the polymer of the platform 62 and any ingrowth oradhesive material that may be present at the interface of the convexmedial surface 66 of the glenoid component's platform 62 and the glenoid14 of the patient's scapula (see FIG. 5).

As the flexible wire saw 16 is inferiorly advanced with suchreciprocating motion, it encounters and cuts through the polymer anchors68 of the implanted glenoid component 12. For example, in theillustration of FIG. 5, the flexible wire saw 16 has cut through one ofthe glenoid component's stabilizing pegs 74 and is partially through itsfinned central peg 70.

The surgeon continues to inferiorly advance the flexible wire saw 16with reciprocating motion until the saw 16 exits from behind the glenoidcomponent's platform 62. Specifically, the surgeon continues toreciprocate the flexible wire saw 16 until it passes beyond theinferior-most edge 80 of the glenoid component's platform 62. At thatpoint, each of the glenoid component's anchors 68 have been cut through.The surgeon may then lift away the freed platform 62 of the glenoidcomponent 12 from the patient's glenoid 14. As can be seen in FIG. 6,the newly cut anchors 68 (e.g., the finned central peg 70 and thestabilizing pegs 74) remain in the bone of the glenoid 14 once theplatform of the glenoid component 12 has been removed.

As shown in FIG. 6, the anchors 68 may then be removed from the bone ofthe glenoid 14 to complete the removal of the glenoid component 12. Forexample, each of the stabilizing pegs 74 may be removed by selecting adrill bit 82 having the same diameter as the bit that was used to drillthe holes 76 in the glenoid 14 of the patient's scapula during theprevious surgical procedure (i.e., the primary procedure in which theglenoid component 12 was originally implanted). Such a similarly-sizeddrill bit 82 may then be used by the surgeon to drill the stabilizingpegs 74 out of the bone. The finned central peg 70 may likewise beremoved by use of drill bit (not shown) having the same diameter as thebit that was used to drill the hole 72 during the previous surgicalprocedure.

Once the anchors 68 (e.g., the finned central peg 70 and the stabilizingpegs 74) have been removed, the surgeon may then perform the remainderof the revision surgical procedure, including the implantation of arevision glenoid component (not shown) into the patient's glenoid 14.

It should be appreciated that although the cutting procedure is hereindescribed as advancing inferiorly away from the superior-most edge 78 ofthe glenoid component's platform 62 in the direction toward itsinferior-most edge 80, other techniques may also be used. For example,the flexible wire saw 16 may be advanced superiorly, medially,laterally, or some combination thereof.

Turning now to FIGS. 7 and 8, there is shown a surgical procedure inwhich the surgical saw assembly 10 is used to surgically resect thenatural humeral head 90 of a patient. Such resection of the humeral headis performed in shoulder arthroplasty procedures when it is necessary toreplace the patient's natural humeral head 90 with a prosthetic head.

In the preliminary steps of the surgical procedure, the patient's softtissue is dissected and retracted to allow access to the patient'shumeral head 90. Full (i.e., 360°) exposure of the humeral head 90 istypically achieved. As can be seen in FIG. 7, the distal end 36 of theprotective cannula 18 is then inserted into the surgical site formed bythe dissected and retracted soft tissue. The surgeon then positions theflexible wire saw 16 in contact with the patient's humeral head 90. Inparticular, the surgeon slips the loop 34 formed by the middle section32 of the flexible wire saw 16 around the humeral head 90 such that theinside of the loop 34 contacts the humeral head 90. In the illustrativeembodiment described herein, the surgeon slips the loop 34 formed by themiddle section 32 of the flexible wire saw 16 around the humeral headsuch that the inside surface of the loop 34 is in contact with theposterior surface 92 of the humeral head 90.

If not already installed, the surgeon then secures a handle 22 to eachend of the flexible wire saw 16 by inserting the handle's hook 24 intothe loops 20 formed on the ends 26, 28 of the saw 16. The surgeon thengrasps a handle 22 with each hand and reciprocates or otherwise pullsthe flexible wire saw 16 back and forth. The surgeon also appliespressure on the flexible wire saw 16 so that it advances anteriorly. Asthe flexible wire saw 16 is advanced anteriorly away from the posteriorsurface 92 of the humeral head in the direction toward its anteriorsurface 94, the reciprocating motion of the saw 16 abrades the bonetissue of the humeral head 90.

The surgeon continues to anteriorly advance the flexible wire saw 16with reciprocating motion until the saw 16 exits the bone. Specifically,the surgeon continues to reciprocate the flexible wire saw 16 until itpasses beyond the anterior surface 94 of the humeral head 90. At thatpoint, the surgeon may then lift away the resected portion of thepatient's humeral head 90. As can be seen in FIG. 8, the surgicallyprepared surface 96 of the humeral head 90 is substantially planar.

Once the substantially planar surgically prepared surface 96 of thehumeral head 90 has been created, the surgeon may then perform theremainder of the surgical procedure, including the implantation of ahumeral stem component (not shown) into the intramedullary canal of thepatient's humerus.

It should be appreciated that although the humeral cutting procedure isherein described as advancing posteriorly away from the anterior surface94 of the humeral head 90 in the direction toward its anterior surface94, other techniques may also be used. For example, the flexible wiresaw 16 may be advanced posteriorly, medially, laterally, or somecombination thereof.

It should also be appreciated that other embodiments of the protectivecannula 18 may be used in the humeral cutting procedure described inregard to FIGS. 7 and 8. For example, the protective cannula 18 may beembodied as a cannulated ring having the flexible wire saw 16 capturedtherein. Such a cannulated ring provides support for the flexible wiresaw 16, while also allowing the surgeon to size the humeral head.

Although the various cutting procedures disclosed herein areillustratively described as manual cutting techniques in which thesurgeon manually reciprocates the flexible wire saw 16, other techniquesare also contemplated for use. In particular, the flexible wire saw 16,with or without modification thereto, may be used in conjunction with apowered surgical tool. In such a case, the powered surgical toolsupplies the motive power to move the wire saw 16 in lieu of thesurgeon's manual motion.

While the disclosure has been illustrated and described in detail in thedrawings and foregoing description, such an illustration and descriptionis to be considered as exemplary and not restrictive in character, itbeing understood that only illustrative embodiments have been shown anddescribed and that all changes and modifications that come within thespirit of the disclosure are desired to be protected.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the apparatus, system, and method describedherein. It will be noted that alternative embodiments of the apparatus,system, and method of the present disclosure may not include all of thefeatures described yet still benefit from at least some of theadvantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the apparatus, system, andmethod that incorporate one or more of the features of the presentinvention and fall within the spirit and scope of the presentdisclosure.

The invention claimed is:
 1. A method of surgically resecting a humeralhead of a patient, comprising: creating an incision in the patient togain access to the humeral head, positioning ends of a flexible wire sawthrough a protective cannula such that the flexible wire saw forms aloop extending out of the protective cannula, positioning the looparound the humeral head in contact with a posterior surface of thehumeral head of the patient, and reciprocating the flexible wire sawwithin the protective cannula while advancing the flexible wire sawanteriorly away from the posterior surface so as to cut through thehumeral head of the patient so as to create a substantially planarsurgically prepared surface.
 2. The method of claim 1, wherein: theprotective cannula comprises a dual-lumen cannula having a first cannulaand a second cannula, and positioning the ends of the flexible wire sawin the protective cannula such that the flexible wire saw forms the loopextending out of the protective cannula comprises positioning theflexible wire saw in the protective cannula such that (i) a first end ofthe flexible wire saw extends out of a first end of the first cannula,(ii) a second end of the flexible wire saw extends out of a first end ofthe second cannula, and (iii) a middle section of the flexible wire sawextends between a second end of the first cannula and a second end ofthe second cannula.
 3. The method of claim 1, wherein positioning theends of the flexible wire saw in the protective cannula comprisespositioning ends of a Gigli saw in the protective cannula.